EXHAUST GAS PURIFICATION SYSTEM

摘要

Disclosed is an exhaust gas purification system (100) that can prevent adherence of aqueous urea in a dosing valve during DPF regeneration. When a DCU (126) has received a DPF regeneration authorization request from an ECM (125), the DCU (126) controls a supply module (106) in a manner so as to jet or return to a urea tank (105) aqueous urea within the dosing valve (104) in order to eliminate the aqueous urea that has collected within the dosing valve (104), and afterwards, confirms that the amount of NH3 of an SCR catalyst has become at or below a stipulated value and transmits a DPF regeneration authorization to the ECM (125).